| 摘要 |
1. A measuring sensor for an arrangement for determining the amount of the fluid flowing through a pipe system, by means of the transit time difference of ultrasonic pulses in and opposite to the direction of flow, comprising two ultrasonic transducers (2, 3) which are arranged at oppositely disposed ends of a measuring pipe portion (1) of the pipe system and which can be respectively operated as a transmitter and as a receiver and which in the transmitting mode induce in the measuring pipe portion modes of oscillation which respectively include a spatial fundamental wave (6) with a substantially even profile over the cross-section of the measuring pipe portion, and spatial harmonics (7, 8) in relation to said fundamental waves, and which in the receiving mode generate and output signal (U2 ) corresponding to the respectively received mode of oscillation, characterised in that, in the case involving the production of modes of oscillation with a harmonics component which is respectively smaller or larger in comparison with the fundamental wave component, the two ultrasonic transducers (2, 3) are arranged at such a spacing from each other that the phase angle (gamma) between the ultrasonic oscillations of the receiving mode of oscillation and the harmonics component relative to that mode of oscillation, with the fluid still, is approximately 90 degrees or 0 degree respectively. |
